The exclamation mark symbol is the brake differential pressure warning light. The brake system is split (different ways -"L". "V" depending on which model). This warning light comes on if a difference in pressure is detected between the 2 parts of the system. This could be because of a leak. If you have air over hydraulic brakes, there will be 2 brake master cylinders mounted on the right hand chassis rail (outside). Each master cylinder has a reservoir (a translucent plastic container with a black plastic screwed cap). Check both of these and make sure they are full of brake fluid. You may find one of them is empty!
JD
July 2009
if it's fitted with a tachograph it may be the led for speed setting,can be adjusted to come on at a set speed.
k
July 2009
Automatic Answer
We may have found other answers which could help you.
howtomendit.com for free repair help, information and advice.
Try fixfault.com to fix lorries/trucks.